Embodiments relate to a construction for determining pass bits of a nonvolatile memory device.
In recent years, there has been an increasing demand for nonvolatile memory devices which can be electrically programmed and erased and which do not require the refresh function of rewriting data at specific intervals.
The nonvolatile memory device is configured to enable electrical program and erase operations, and perform the program and erase operations through the threshold voltage of a cell which varies when electrons are moved by applying a strong electric field to a thin oxide layer. During the programming operation of the nonvolatile memory device, a verification operation for determining whether a cell to be programmed has been programmed to exceed a reference voltage is performed.
In performing such a verification operation, a point of time, at which the cell is programmed to exceed the reference voltage, is sought to be checked. Furthermore, there is a need to check a point of time at which the number of cells programmed to exceed a reference voltage reaches a predetermined number.